Method for conditioning aik



Nov. 18, 1941. w. H. CARRIER. 21,946

METHOD FOR CONDITIONING 'AIR Original Filed June 10, 19:53

ATTORN EY UNITED STATES PATENT METHOD FOR CONDITIONING AIR Willis H. Carrier, Essex Fells, N. 1., assignor to Auditorium Conditioning Corporation, a corporation of New Jersey riginal No. 1,956,707, dated May 1, 1934, Serial OFFICE No. 675,177, June 10, 1933.

Application for reissue November 26, 1935, Serial No. 51,660

2 Claims.

cooling fluid circulates and controlling the temperature of the cooling fluid. The temperature of the air leaving such adevice is dependent upon the character and extent of the surface, the air velocity and the temperature of the surface. Likewise, the moisture content of the leaving air depends uponthe character and extent of the surface. the air velocity, and the temperatur of the surface. Both the temperature and the moisture content of the air leaving such a device are subject to the entering temperature and moisture content conditions of the air. In a device of this character, it is not possible to remove moisture without also removing sensible heat of lowering the surface temperature. Beyond this particular, point, however, the process is reversed, the amount of heat removal increasing with respect to the moisture removal, as the temperature is further lowered. Thus it will be seen that by varying the amount of contactof the air by changing the amount of effective surface and at the same time changing the refrigerant temperature it is possible to obtain any relation return air it. maybe desirable in such an, in-- quantity of air treated trol the humidity and temperature of air simultaneously and independently within an enclosure by means of refrigeration under variable heat load.

Another object of the invention is to provide a method for the control of humidity and temperature by surface cooling wherein the area of the cooling surface is varied and the temperature of the cooling medium is varied independently and simultaneously as required by the conditions in the enclosure.

A still further object of the invention is to control the humidity and temperature of air by surface cooling, varying the proportion of the air contacting with the effective cooling surface of temperature and dewpoint reduction desired within the known psychrometric limitations.

. This invention provides a control of the tem- I perature of the air supply to the room as well as a control of the humidity simultaneously'but independently by the simultaneous and independent for the variation of the proportion of fresh'and whereby the temperature of the air emitted may be maintained at the desired temperature and at the same time the humidity may be varied; or the humidity may be increased and the temperature lessened.

Other objects will appear more fully hereinafter.

Referring to the drawing the figure is a diagrammatic plan view of a method of controlling humidity and temperature independently within an enclosure embodying the principles of my invention.

In carrying out my invention I propose to provide a fresh air intake through duct l' with damper 2' therein leading into mixing chamber 3". From the enclosure 8' the return or recirculated air is brought through duct 4 leading into mixing chamber 3'. A damper 5' is in duct 4'. The mixed airs are drawn from mixing chamher 3' through the conditioner 20' by fan 1' which in turn'delivers the conditioned airs into' enclosure 8. The coils 30 .may be a series of coils, plates or the like-or a single extended coil.

I have provided a series arrangement in which the refrigerant is expanded in on the side of the coil over which the conditioned air leaves the conditioner and the suction side of the coil is Valve 3| would be set to give a superheat from five to ten degrees above the normal evaporating temperature and is sodeslgned and constructed that it gives the necessary degree of superheat regardless of the pressure in the coil. It should be noted that the coldest gas is in contact with the leaving air and the warmest gas which is superheated is in contact with the warmer entering air. That is, there is a countercurrent flow to prevent the conditioned air from again picking up moisture. 1

This arrangement does not of itself give control of temperature. and humidity. I .propose to I do this-by varying the refrigerant temperature or the amount of surface which is exposed. I propose to vary the amount of effective or contact surface by independently controlling the supply of refrigerant passing through the master valve III. This may be done in a variety of ways but I have shown a series of expansion orifices 35, 3B, 31, which are each provided with valves 38,. 39, 40. These valves may be operated by compressed air of electrically operated solenoid valves as shown. The suction line 34 is connected to a compressor 28' having normally a constant displacement and discharging into a condenser 4| through pipe 42. Pipes 34 and 42 are connected by a pipe 43 with throttling valve 44 and connection 45. This valve may be set to' maintain a minimum suction temperature of say twenty-iive degrees. The valve is similar to a'steam regulating pressure valve. This will prevent objectionable frosting on the coil under any conditions of operation particularly as the compressor is of the positive type, either piston or rotary, and will displace a constant volume during operation. The refrigerant handled through the coil will varyin temperature from a possible maximum of 50 to 25 for which throttling valve 44 .is set. The gradation of temperature is accomplished-by admitting greater or lesser amounts of refrigerant through the orifices 35,36 and 31, by. opening or closing either automatically as shown,

It should be noted that by this method of control the amount of effective surface of the cooling coil is also varied. The pressure air for the thermostat ill and hygrostat 48 for operating the valves is from'tank 49.

Certain modifications might be made and still fall within the'scope of my invention. A single expansion valve of variable opening might be made to accomplish the same result through graduated action as is accomplished by the valves 38, 39 and 40, more than one compressor might be used, a series of cooling surfaces might be used and in such case with more than-one compressor an intermittent operation of the compressors themselves may be employed in place ofhumidity of air which comprises directing the air 1 through a chamber, admitting refrigerant to a path in said chamber adjacent the polntwhere the air leaves said chamber, initiatin evaporation of said refrigerant near said point, directing the refrigerant through said path and withdrawing the same from said path adjacent to the point where air is admitted to said chamber, con trolling the superheat on the suction side of said path, controlling the quantity of refrigerant admitted to the said path, controlling the minimum suction temperature and controlling the back pressure to predetermine the temperatureof the refrigerant to control the relative humidity of the air being conditioned.

2. A method of producing desired conditions of temperature and humidity in the atmosphere of an enclosure, said method consisting of moving refrigerant through a circuit including a single passage, evaporating the refrigerant in said pasreverse taking place as the pressure falls. For f instance, valve being closed, only 75% of the refrigerant will pass through-the oriflces.- The closing of valves 40 and 39 will permit but 50% and the closing of all the valves will permit but 25%. A further reduction below 25% will shut down the apparatus. By interposing'an addi tional by-pass valve 41 it is possibleto control the back pressure and therefore the temperature of the refrigerant in the coil. Valve 41 may be manually operated or by hygrostat 48. By this independent but simultaneously acting control it is possible to control either manually or automatically both. the amount of refrigerant and the temperature of the refrigerant within the coil.

sageby circulating air for the enclosure in heat exchange with the refrigerant in the passage,

liquefying the refrigerant in a portion of said circuit, reducingthe pressure of the refrigerant subsequent to liquefaction, supplying therefrigerant subsequent to said pressure reduction to the inlet of said passage, controlling said'supplying by directing the refrigerant through one or more of a plurality of parallel paths feeding to said inlet, said controlling being eifected by open, ing and closing said paths successively to the flow.

of refrigerant therethrough responsive to successive changes in temperatureof the air within the enclosure, whereby different portions of the passage will successively become respectively effective or ineffective for the dehumidiflcation of air circulated in contact therewith.

Wings 11. CARRIER. 

